Process for preparing telomers from ethylene and alpha, omega-dibromoperfluoroalkylalkanes in the presence of organic free-radical generators

Abstract

A process is disclosed wherein a telomer having the formula BrCH 2 CH 2 (CF 2 CFX) n CH 2 CH 2 Br is prepared by reacting a telogen of the formula Br(CF 2 CFX) n CH 2 CH 2 Br with ethylene in the presence of an organic free-radical generator, wherein X is fluorine or a trifluoromethyl radical and n is an integer having a value of 1-5. It has been found that, when at least 0.05 mole of said free-radical generator is used for each mole of said telogen, the conversion of the telogen to the telomer is surprisingly increased.

That which is claimed is: 
     
       1. In a process for the preparation of a telomer having the formula BrCH 2  CH 2  (CF 2  CFX) n  CH 2  CH 2  Br comprising reacting a telogen of the formula Br(CF 2  CFX) n  CH 2  CH 2  Br with ethylene in the presence of an organic free-radical generator, wherein X is independently selected from the group consisting of a fluorine radical and a trifluoromethyl radical and n is an integer having a value of 1-5, inclusive, the improvement comprising using at least 0.05 mole of said free-radical generator for each mole of said telogen. 
     
     
       2. The process according to claim 1, wherein said free-radical generator is an organic peroxide. 
     
     
       3. The process according to claim 2, wherein the value of n is 1 to 3, inclusive. 
     
     
       4. The process according to claim 3, wherein X is fluorine. 
     
     
       5. The process according to claim 4, wherein n is 1. 
     
     
       6. The process according to claim 5, wherein 0.06 to 1.8 moles of said organic peroxide is used for each mole of said telogen. 
     
     
       7. The process according to claim 6, wherein 0.1 to 0.2 mole of said organic peroxide is used for each mole of said telogen. 
     
     
       8. The process according to claim 7, wherein said organic peroxide is t-butyl peroxide. 
     
     
       9. The process according to claim 1, wherein the value of n is 1 to 3, inclusive. 
     
     
       10. The process according to claim 9, wherein X is fluorine. 
     
     
       11. The process according to claim 10, wherein n is 1. 
     
     
       12. The process according to claim 11, wherein 0.1 to 0.2 mole of said free-radical generator is used for each mole of said telogen. 
     
     
       13. The process according to claim 1, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres. 
     
     
       14. The process according to claim 2, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres. 
     
     
       15. The process according to claim 5, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres. 
     
     
       16. The process according to claim 6, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres. 
     
     
       17. The process according to claim 7, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres. 
     
     
       18. The process according to claim 8, wherein said process is a flow-through process carried out at a pressure of 1 to 2 atmospheres.